package com.whu.tcx01.utils;

public class CoorTrans {
    public static final double EARTH_RADIUS=6378137;
    private static double rad(double d)
    {
        double result = d * Math.PI / 180.0;
        return result;
    }

    //根据经纬度求距离（米）
    public static double GetDistance(double lng1, double lat1, double lng2, double lat2)
    {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a/2),2) +
                Math.cos(radLat1)*Math.cos(radLat2)*Math.pow(Math.sin(b/2),2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000) / 10000.0;
//        System.out.println(s);
        return s;
    }

}
